The cheapest Dublin to Boston return flight on the radar right now is €351, flying with Icelandair via one or more connections. It covers departures in January 2027, and every dated link below opens that exact DUB–BOS search on Skyscanner. That is roughly 18% below the €429 this route usually costs. Across 84 recorded checks it has ranged between €163 and €669. Our sampling points to January 2027 as the cheapest month to fly Dublin to Boston.
Prices are re-checked against Skyscanner automatically, and every one shows when it was last confirmed, so nothing here is older than it looks. Not flying from Dublin? We track 51 other departure cities for Boston, listed at the foot of this page.
Prices like this tend to vanish fast. If it has gone when you look, try the days either side of the dates above, since Dublin to Boston is often still worth booking within a day or two of the fare we found.